That really is a tricky one.
I take it they both have a full Triumph Service History ??
Personally, I would be a bit cautious of a 13 year old bike with only 11k miles on the clock, unless this is backed up with the service history and MOT (or whatever you call them over there). Surely a bike that old would have more miles.
I know a few people who disconnect the speedo on a regular basis to show a much lower mileage when they come to sell. A couple of ways to check is the condition of the rubber footpegs and gear lever rubber. Well worn equals higher mileage.
Not much help I know, but I would have to see and hear the bikes